The present invention relates generally to control apparatuses for internal combustion engines, and more particularly to a combustion control apparatus for an internal combustion engine with an exhaust purifier such as a particulate filter, which is configured to decrease an excess air ratio of the engine, and to raise an exhaust gas temperature of the engine, without increasing exhaust smoke.
In recent years, there have been disclosed various techniques of raising an exhaust gas temperature to activate an exhaust purifier for an engine with an exhaust purifier in an exhaust gas passage. One such technique is disclosed in Japanese Patent Provisional Publication No. 2000-320386, especially in paragraphs [0106] through [0111]. In this technique, a basic fuel injection quantity to produce a desired engine torque is calculated in accordance with an operating condition of the engine. The basic fuel injection quantity of fuel is supplied to a cylinder of the engine by multiple fuel injections near top dead center (TDC).
On the other hand, a known method of removing particulate matter (PM) from exhaust gas employs a particulate filter. The particulate filter includes a porous filter element to filter exhaust gas to remove PM. When the accumulation quantity of PM in the particulate filter exceeds a specific quantity, the backpressure of the engine rises, to cause a trouble in the operation of the engine. Accordingly, it is necessary to dispose of PM at intervals to regenerate the particulate filter. A known method of PM regeneration raises exhaust gas temperature to raise a bed temperature of the particulate filter, which results in burning PM.